Montaigne
Montaigne on the body, sex, marriage and everything else...
Reading Montaigne is not for everyone, but one of its pleasures is stumbling across the many witty insights about the "rebellious and tyrannical" penis, women's dildos, huge codpieces, impotence and the like. As many have said, he seems strikingly contemporary.
It is best to simply quote the man, so the following are from Essais III, V - "On some lines of Virgil," one of his best essays, in The Complete Essays, a translation I have by M.A. Screech.
Aristotle says that we should approach our wives wisely and gravely for fear lest we unhinge their reason by arousing them too lasciviously. What he says for our moral sense the doctors say for our health's sake, namely that too hot, voluptuous and unremitting a pleasure is deleterious to the sperm and impedes conception. They go on to say that in the case of the kind of intercourse which is feeble by nature (as the married kind is) we should undertake it rarely, at stated intervals, so as to fill it with a just and fruitful heat.
If you missed the irony in those lines you will miss Montaigne altogether.
Try this:
Any man who can without dying of shame await the morning which brings disdain from a pair of lovely eyes, conscious of his flaccidity and irrelevance, has never known the happy pride of turning them glazed and dim by the vigorous exercises of a fulfilled and active night.
Or this:
A wife may give herself to another man whom - not because of the state of his finances but because of his very personality - she would never wish to marry. Few men have married their mistresses without repenting of it.
And to end:
The whole movement of the world tends and leads towards copulation.
Indeed it does. Below is the Tour de Montaigne - the "tower" or library in which Montaigne worked and then, below that, the Château today. The Tower is original - it is all that has survived when the original Château de Montaigne was burnt down in a fire in 1885. It was quickly rebuilt. Official link here. The Château is way to the south of the town of Saint-Michel-de-Montaigne, and it sits on the north bank of the Dordogne River, east of Bordeaux.